Multiple Choice Questions
Some students connect four lightbulbs of equal resistance as shown in the figure below.
- Which of these are the same circuit as the students made.
- It was D, but in case he switches it up, look at the pictures and see which matches up. What I did was look at the top of the battery and noted that it was connected to A and C, which ruled out one of the drawings, then noted that the bottom of the battery was connected only to B, and B was connected to C and D. Only one of the drawings matched.
- If lightbulb C was disconnected, what would happen to the brightness of bulb B?
- It would get dimmer.
- Rank the brightness of all the bulbs from 1 being the dimmest, and 4 being brightest. Us the same number for bulbs of equal brightness.
- A = 1 (A and D are equally bright and both the dimmest.)
- B = 4 (the brightest since it has the most current running over it.)
- C = 3 (the next brightest)
- D = 1 (A and D are equally bright and both the dimmest.)
I made a simulation of with and without C below.
Consider the drawing below.
- There is an unmarked charge in this drawing, mark it with an A
- Is point a positive, negative, or neutral?
- Draw field lines from the three marked spots by the R charge, and indicate direction.
- Which direction would the force be if you placed a +1C charge on points A and B?
- Both A and B would be to the left.
- In which drawings would you need to do the most work to move a particle from point A to B?
- I put the work would be the same because work does not care about distance in this case, just that it is moving from PE 20V to 40V.
I forgot to get numbers for some of these, but I have the equations, so I have put different numbers then may have been given, but the equations and answers are the same. (I may be totally wrong on any of them, but I think the are correct. Let me know if you see any errors in the questions, equations or answers.)
Q1 You have two plates (a capacitor)
You are given C and V and need to find Q.
C = 6.3μF =
V = 7.6V
You have the same plates as before except now there is a dielectric between them and now holds a charge of . Find the value of the dielectric.
[Note the varible for the dielectic constant is “k” and is always larger then 1 and has no units]
The actual answer is k = 1.5
There is a wire with 15V and 0.33A. What is its resistance?
There is a cell membrane where the inside is less then the outside. The thickness of the outside wall is